M- schwartz



M. SCHWARTZ MULTIOFFICE AUTOMATIC 'TELEPHONE SYSTEM June 23, 1931. `Re. 18,113

Original Filed Feb. 8,y 1924. 8 Sheets-,Sheet 'l 'E f f Figi l H F194 Flgf "o QW@ waff? auf/@#0) aff/ff? @d WMM? fn- M. S HWA T June 23, 193g. c R -z Re. 18,113

MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM 8 Sheets-Sheet 2 M. SCHWARTZ June-23, 1931.

MULTIOFFLCE AUTOMATIC TELEPHONE SYSTEM eet 3 M. scHwARTz June 23, 1931. Re.- 18,113

' MULTIOFFICE AUTOMATAIC TELEPHONE SYSTEM Original Filed Feb; 8, 1924 8 Sheets-Sheet 4 (cada) lli/'1:11551 Echr/E www Eff-- M. SCHWARTZ June 23, 1931.

MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM 11 \\\m. l\\\ IN@ Il hun. mwwwllx Wm a sheets-sheet 5 Original Filed Feb. 8, 1924 -Inuan U12- Mcha'e SC2-m M. SCHWARTZ `lune 23, 1931. Re. 18,113

MULTIOFFIGE AUTOMATIC TELEPHONE SYSTEM Original Filed Feb. 8, 1924 8 Sheets-Sheet 6 June 23, 1931 M. scHwARTz MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM Ref-.5,18

Original Filed Feb. 8, 1924 M. SCHWARTZ June 23, 1931. Re. 18,113

MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM Original Filed Feb. 8, 1924 8 Sheets-Sheet 8 Inman 01"- Y Makes? 55km Reissued June 23, 1931 UNITED STATES PATENT OFFICE TO AUTOMATIC ELECTRIC INC., OF WARE CHICAGO, ILLINOIS, A oo'R-PoRATIoNVoF DELA- MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM Original application led February 8, 1924, Serial No. 691,327. Renewed October 24, 1927.

Application for reissue led .Tune 18, 1930. Serial No. 462,115.

1,674,134, dated June 19, 1928.

The present invention relates to multioiiice automatic telephone systems in general, but is concerned more particularly with systems of the above character in which call directors are employed to register, translate, and retransmit the part ofV the number which is indicative of the oflice called, and the broad general object, briefly stated, may be said to consist in the provision of new and improved circuit arrangements whereby the subscriber digits (the part of a number indicative of the desired line in the particular office called) of a telephone number may be translated also and in such a manner that the capacity of a given train of automatic step by step switches may be increased so as to accommodate a larger number of subscribers Without increasing the number of switches in the train.

There are many other objects, several of which are more or less incidental tothe carrying out of the main object, all of which will be best understood from a further perusal of the speciiication.

Referring now to the drawings comprising Fi s. 1-12, inclusive, Figs. 1-4, inclusive, show fbur trunking layouts which are to be used in explaining the objects and features of the invention, while Figs. -11, inclusive, show a suflicient amount of apparatus employed in a telephone system embodying the principles of the invention to enable the invention to be understood and its utility appreciated, and Fig. 12 shows how Figs. 5-11, inclusive, should be placed together.

Referring now to Figs. 1-4, inclusive, Fig. 1 is a representative layoutof a 10,000-line office employing the standard ten-level selectors. Only five levels, however, of the thousands selectors are used and the capacity of the office, which accordingly would other- Wise be only 5,000 lines is brought back to 10,000 lines by the use ofQOO-line connectors.

Fig. 2 shows a layout oit' two 10,000 line offices in which the same thousands and hundreds selectors are used for both olices; in which G-line connectors are used, as in Fig. 1;- and in which the hundreds selec- Original No.

tors are of the twenty-group type instead of the ten-group type shown in Fig. 1.

p Fig. 3 is a layout of a 10,000-line ofiice and is somewhat similar to Fig. l, except that twenty-group hundreds selectors are used instead of the 20G-line connectors shown in Fig. 1.

Fig. 4 is a layout similar to Fig. 3, except that the capacity of `the connectors shown in Fig. 3 has been increased to 200 lines and the second or lower half of the connector banks is used to accommodate a second 10,000 line office.

Referring now more particularly to Fig. 1, the first five levels of the thousands selector E are used to trunk calls to ve groups of hundreds selectors, one of which'is represented by the hundreds selector F; The ten levels of the hundreds selector F are used to trunk to ten groups of 200fline connectors, of which one group is represented by the 200-line connector H.

Regarding the necessary translation in the telephone numbers, which of course are listed in the directory and called according to the decimal system, it may be pointed out that'in case the thousands digit is anything from 1 to 5, inclusive, it is not' translated, but if the thousands digit is anything from 6 to 0, inclusive, five isv subtracted from it, or in other words, the digits 6 to 0, inclusive, are combined with the digits 1 to 5, inclusive. i

At this time it may be pointed out, that, since only iive levels of the selector E are used to trunk calls to 10,000 lines, each of the ive following groups of switches handles more calls than if ten levels of the selector E were used to handle the same number of calls. In this Way, a considerable saving in the total number of switches can be made owing to kthe increased trunking efficiency that is made possible whenever two relatively small groups can be combined into one larger group.

Regarding the translation necessary in order to choose between the two Wipers of the connector H, it may be pointed out that the set of banks on the connector H that are used depends upon the thousands digit. If this digit is anything :from `1 5, inclusive,

lovery the' ba being vbrought `sets oi wipe the upper set of banks of the connector H is used, while if this digit is anything from 6-0, inclusive, an artificial series of eleven impulses is sent to the connector H after the vertical movement and beiore the regular numericah'otary movement, resulting inthe wipers of the with the up er bank being rotated entirely of contacts, and' resulting in the' wipers of the lower bank (which are set at such an angle that they are not brought into operative relationY with the associated bankcontacts unless the eleven preliminar rotary steps are' taken by` the switchv shaft into position ready to be rotated over the bank as soon as the next and last series of impulses is deliveredv In up the layout of Fig., l, it may be pointed out that ten se rate groups of numbers are combined intoI lve compositeA groups, repnesontedby the first five levels of the thousandsselector, and are later separatedy automatically on theV banks of the 20G-line connectors,

Referring now' particularly to Fig. 2, it ma be pointdfontthat this trunking layout is 'Estant from that shown in Fig. 1, only in that the hundreds selector F is of the twenty-group typt; This selector has two rsl and a preliminary wiperselecting digit' must be delivered to it ahead of the'y regular series of impulses which operatea it to select a trunk, the circuit arrangements being such that if oice No. 2 is called the wiper-selecting digit is 2 and the upper bank is used, while if oce No.y 2 is called, the wiper-selecting digit is 3 and the lower' bankof selector F is used.

Referring now particularly= to Fig. 3, it muy be pointed out that the thousands digits 6.0, inclusive, when; this oiice is called, are combined with the thousands digits 1-5, inclusive, respectively, in thexmanner pointed out above inl connection with Fig. 1. v In the layout shown in Fig,.3, however, the thousands digit controls the sending out of the wiperl selecting. digit to the hundreds lselectors, such.l ais ythe selector lF2, instead'of controlling the sending out of a reliminary wiperf-selecting series of eleven impulses to pick out connector wipers as in the case of Fig, 1. It is thhs vseen that the scheme shown inFig.- 1, and the schema shown in Fig. 3 are simply two dierentmethods of obtain'- ingthesnme result as regards the capacity of' the switch train, and'it may be pointed out that the traic conditions may be such in one n oice: as to make the use ofL one layout expedient, while the traiiic conditions in another oce of the same-system maybe such that the' use1 of the` otherl layout is more economical, oritmay even happen-that two smaller telephone systems, origmally owned and operated by diflerent interests, are later consolidated into one large system, in which connector H ywhich cooperate tors, such'as H5', are of the 20G-line type instead -of the 10G-line type.

In this latter case, one bank of any one connector, such as H*F for example, represents lines in one oiiice,

While the other bank of the same. connector represents lines in a different oilice. Accordingly the sending out of the preliminary series of eleven impulses between the vertical movement and the regular rotary movement of the connectors is controlled according to which of the two oiii'ces is called.

It may be pointed out at this time that the capacity of any one of the four trains of switches shown in Figs. 1-4, inclusive,

may be doubled. When this isdone, the

tra-Hic tonthe hundreds selectors and connectors shown is handled in the same way as described hereinbefore and, inaddition, the upper lfive levels of the thousands selectors, instead of being left dead, are used to trunk calls through a new group of hundreds selectors and'thence by wary of the connectors to the called lines. After this is done, when a number is called which must be reached by Way of one of the upper five levels of a thousands selector, the thousands digit is sentv out untranslated in caseA it is any digit from 6 to 0, inclusive, but translated. in case it is -any digit from 1 to 5, inclusive, the translation being such that the thousands digit 1 becomes a 6; the-thousands digit 2 becomes a 7 etc. Accordingly, when either of the layouts shown in Figs. 2 and 4 is used for both halves of the thousands selector banks four 10,000-line oflices located in the same building may be accommodated withy one set of thousand selectors and with only three local switches involved in any one vcon- 'nectiorL Referring now to Figs. 5-11, inclusive, Figs. 5, 6, and' 7 show the switching equipment employed for a connection from the line of' substation A, Fig. 5, to either of the two substations, A or A2, Fig. 7, which substations are also represented iny Fig. 2 as accessible to the connector H2; and Figs. 8-11, inclusive, show by means of the usual circuit diagrams one of the call directors employed in making the necessary. translation both inthe oice digits and the subscriber digits of the numbers.

Fig. 5 shows the line switch C in which the line of substation A terminates and also the trunk circuitl TC, which is one of the trunk circuits accessible to the line switch C. This trunk circuit is individual tothe selector D and hasassociated with it the secondary switch SS which selects an idle director when the trunk circuit TC is taken for use.

Fig. 6 shows the thousands selector E which is denoted in this drawing by means of the dotted rectangle bearing that reference character. The selector E is accessible to the selector D, Fig. 5, and has access to second selectors of which the selector F is one. 4The trunking may be readily appreciated by referring back to Fig. 2.

Fig. 7 shows the 200 line lconnect-or H2 whose upper Wipers 251-253, inclusive, are used to coinplete the connection when the eleven preliminary rotary steps are not taken by the switch shaft. The lower set of wipers 261-263, inclusive, are used to complete the connection in case the eleven preliminary rotary steps are taken. The fact that the lower wipers are set at an angle with the banks is indicated diagrammatically in the drawings.

Referring now particularly to the director shown in Figs. 8-11, inclusive, the portion 1 of the director shownin Fig. 8 comprises the impulse-control sequence switch S and the associated relays 301 and 302, together with the stop-conductor-control sequence switch S; the portion of the director shown in Fig. 9 comprisesthe sendingr switch SEN, together with the associated relays 40S-405, inclusive, and the release relay 402; the portion of the director shown in Fig. 10 comprises the intermediate distributing frame IDF, the office register GR, and the associated relays 521-525, inclusive; and the portion of the director shown in Fig. 11 coniprises the digit registers DR-1DR-4, inclusive, together with the translating relays 609 and 610.

The present system, having been thus described generally, will now be described in connection with a detailed description of the operation of the apparatus shown. For this purpose it will be assumed that the subscriber at substation A, Fig. 1, desires to converse with the subscriber at substation A', Fig. 7. As far as the present invention is concerned, the part of the number designating the desired office is immaterial and no particular number will be assigned. The part of the number, however, which indicates the desired subscriber after the oliice is reached, is 5,000, as may be seen in Fig. 2. Accordingly, the subscriber at substation A removes his receiver and dials the two otlice digits of the number, followed by the four subscribers digits 5-0-0-0.

When the receiver is removed atsubstation A, line relay 15 of the line switch C energizes over line conductors 11 and 12 and places ground 'on private normal Lconductor 13 at armature 20, thereby making the calling line busy immediately and closing .a circuit through switching relay 14 and step- Assuming the trunk to be busy, however,

there is a ground potential upon the test conductor thereof, and this ground potential is extended through test wiper 23 to the junction of switching relay 14 and stepping magnet 16. Switchingrelay 14 is accordingly short circuited and does not energize, and stepping magnet 16 operates in a buzzer-like manner and advances the wipers 22-24, inclusive, step by step in search of an idle trunk.

When an idle trunk is reached, which trunk, it will be assumed, is the one comprising conductors 25-27, inclusive, switching relay 14, being no longer short circuited, energizes. Stepping magnet 16, however, does not energize at this time on account of the high resistance of switching relay 14. Upon energizing, switching relay 14 opens the test circuit and prepares the holding circuit at armature 18, thereby making the seized trunk busy immediately; and at armatures 17 and 19 disconnects the line conductors l1 and 12 from the winding of line relay l5 and ground at armatures 17 and 19 and extends them by .way of wipers 22 and 24,`con ductors 25 and 27, and armatures 43 and 45 and their resting contacts to the windings of line relay 35 of the trunk circuit TC. Line relay 35 thereupon energizes over the calling line and closes a circuit for release relay 36 at armature 38. Release relay 36, upon energizing, places ground on release trunk conductor 26 at larmature 40 thereby completing the holding circuit for switching relay 14 of the line switch C before the slow acting line relay l5 has had time to deenergize. As a further result of the energization of release relay 36 of the trunk circuit TC, it closes at armature 41 a. circuit through switching relay 46 and stepping magnet 47 of the secondary switch SS in series, and at armature 42 connects test wiper 54 to thev junction of switching relay 46 and stepping magnet 47. Accordingly, the secondary switch SS selects an idle trunk in the same manner as above pointed out for the line switch C. In this case it will be assumed that the director shown in the drawings is the first one found to be idle. Accordingly, when the wipers 52-55, inclusive, of the secondary switch SS arrive upon the bank contacts in which the conductors 56-59, inclusive, terminate, switching relay 46 energizes; opens the test circuit and places ground on test wiper 54 at armature 50; connects up the impulse wiper 55 atarmature 51; and at armatures- 48.and 49 connects up wipers 52 and 53, thereby placing a bridge across conductors 62 and 64 of the selector D. This bridge includes wipers 52 and 53 of the secondary switch SS, conductors 56 and 57 and armatures 418 and 421, Fig. 9, and their resting contacts in multiple. Line relay 65 of the selector D accordingly enerand closes a circuit or release relay 66 at armature '76. Release relay 66 thereupon. energizes and places a multiple ground on release trunk conductor 63 at armature 77, and at armature 78 opens a point in the circuit of releasel magnet 71 and prepares a circuit for vertical magnet 72.

In the seized director, release relay 402 energizes responsive to ground being placed on release trunk conductor 58 through test wiper 54 of the secondary switch SS and removes ground from release conductor 401 m at. armature 417. Relay 402 also opens the normal restoring circuit of the sending switch SEN atarmature 416, and at armature 415 opens the normal restoring circuit of the s uence switch S. gg The a ve described operations have all taken place responsive tothe removal of the receiver at substation A, and the apparatus is now in readiness to receive the first oiiice digit in the desired number. When mi the subscriber at substation A manipulates his calling device in accordance with the first oice digit, a corresponding number of interruptionsare produced in the circuit of line relay 35 of the trunk circuit TC, and an each time line .relay 35 deenergizes responsive` to one of these interruptions, it closes at. armature 39 a circuit for vertical magnet 504 of the oiiice register OR, Fig. 10, as follows: from ground by way of. the u, resting contact and armature 39, armature 51 and its working contact, wiper 55, conductor 59, series relay 301, Fig. 8, wiper 310 of the sequence switch S, the first associated bank Vcontact conductor 321 and the vertical 5 magnet 504, Fig. v10, to battery. By the operation .of the vertical magnet 504, the

Vwipers 511-514, inclusive, of the oice register OR are raised step by step until they come to rest opposite the desired level of w bank contacts.V Relay 301, Fig. 8, is energized in series with vertical magnet 504 upon Vthe first impulse of current delivered to the latter, and, being slowV acting, maintains its armature 304 attracted throughout the entire series of impulses. Upon energizing, relay 301 closes a circuit for slow acting relay 302 which accordingly energizes and prepares at armature 305 a circuit for stepping magnet 306 of the sequence switch S.

At the end of the series of impulses delivered to the vertical magnet of the oee register, series relay 301 deenergizes and ens the circuit of slow acting relay 302,

and at the Sametime closes the circuit of,

et stepping magnet. 306 of the sequence switch S, whereupon the wipers 309 and 310 ofthe sequence switch Sy are advanced into engage.- ment with the second set of bank contacts.I An instant later, slow acting relay 302 deenergizes and opens the circuit of stepping magnet 306 at armature 305.

Then the calling subscriber at substation A manipulates his calling device in accordance with the second oli'ce digit, a corresponding series of impulses is delivered over the circuit above traced, to wiper 310 of the sequence switch S, Fig.v 8, and thence byv way of conductor 322 to rotary magnet 503 of the oiiice register OR. VRotary magnet 503 is accordingly operated to rotate the wipers 511-514, inclusive, into engagement with the desired set of bank contacts in the selected level, which in this case is the set 564 which is allotted to office #2. The jumper, associated with the bank contact on which the first code-digit wiper 511 lands is connected at the other end tothe third impulse-stop conductor 433, thereby predetermining that the first code digit to be sent out will be thev digit 3. V

The bank contact on which the second code-digit Wiper 512 lands is connected by means of a jumper to the skip conductor, thereby predetermining that the second code-digit position will be skipped, the trunking layout being such that the desired oiiceis reached at the end of the first code digit. f

The bank contact upon which the grounded wiper 513 lands is connected by means of the associated umper to conductor 542. Accordingly, relay, 609, Fig. 11, energizes. over conductor 542 and disconnects the last five associated bank contacts from the impulsestop conductors 426-440, inclusive, and connects them to the first ve implse stop conductors 531-536, inclusive.` The thousands digits 6-0, inclusive, are thereby combined with the thousands digits Y1--5, inclusive.

The bank contact upon which the grounded wiper 514 lands is connected by means of the associated'jumper to conductor 545. Accordingly, relays 523 and 525 energize in series over conductor 545. Relay 523, upon energizing, disconnects the stop conductor 355 from the skip conductor at armature `530 and connects it tothe third impulse-stop conductor 433, thereby predetermining that a series of three impulses will be transmitted after the thousands selector has been operated and before the registered hundredsA digit is sent out. Relay 525, upon energizing, disconnects conductor 356 from the skip conductor at armature 532 and connects 1t to the wiper 604 of the thousands register Dlt-1. Relay 525 also connects theconductors 549 and 550, associated with the first and second halves, respectively of the bank.

contacts of wiper 604, to the skip conductor and to the eleventh impulse stop conductor 541, respectively. Accordin ly, it is pre-- determined that the setting of te thousands register DR--l will determine whether or not an extra series of eleven impulses shall be sent out between the vertical and rotary operations of the connector switch to be used in completing the call.

By the conjoint action of relays 301and 302, Fig. 8, in response to the second office digit the wipers of the sequence switch S are again advanced one step. lViper 309 at this time closes the impulse circuit, thereby starting the sender SEN, Fig. 9, to send out the first digit in the office code. However, before the description of this operation is taken up the description of the registration of the desired number will be completed.

lVhcn the calling subscriber at substation A manipulates his calling device in accordance with the first subscriber digit 5 in the desired number, the five impulses of current which are transmitted over the previously traced circuit to wiper 310 of the sequence switch S, Fig. 8, are sent over conductor 331 to the stepping magnet 601 of4 the first digit register DR-l, Fig. 11. Accordingly, the wipers 604 and 605 of the digit register DR-1 are rotated into engagement with the corresponding set of bank contacts.

ll'Vhen the calling subscriber manipulates his calling device in accordance with the second subscriber digit 0, the ten impulses cf current thereby produced, are transmitted over the above traced circuit to wiper 310 of the sequence switch S and thence by way of conductor 332 to the stepping magnet of the second digit register Dlt-2. Accordingly, the wiper 606 is advanced into engagement with its last bank contact.

When the calling subscriber dials the third subscriber digit, ten impulses of current are delivered over the impulse circuit to wiper 310 of the sequence switch S, and are thence transmitted by way of conductor to the stepping magnet of the third digit register DR3, resulting in the Wiper 607 being advanced into engagement with its last contact.

lVhen the calling subscriber dials the next and last digit 0 of the number, ten impulses of current are delivered through wiper 310 of the sequence switch S and conductor 334 Itoi' he stepping magnet of the fourthrdigit register DR-4, resulting in the wiper 608 being stepped into engagement with the last bank contact. 1

At the'endof the registration of the last subscriber digit, the wipers 309 and 310 of the sequence switch S are advanced another step and the wiper 310 engages a dead contact, and accordlngly the said wipers remain in this position until the director is freed and the apparatus restored to normal.

The operation of the sending equipment will now be taken up. It will be remembered that upon the cessation of the second series of impulses delivered to the director, which impulses were transmitted to rotary magnet 503 of the oflice Iregister OR, wipers 309 and 310 of the impulse control sequence switch S were advanced into engagement with the third set ofl bank contacts. When this occurs, Wiper 309 connects the grounded interrupter lead over conductor 428 and through the resting contact an armature 426 to sending relay 403. `As soon as interrupter 303 closes the circuit of sending relay 403, the latter energizes and opens a point in the outgoing control` circuit atr armature 418. This, however, does not produce any result owing to the fact that armature 418 and its contact are shunted by armature 421 and its contact. As a further result of theenergization of sending relay 403, it closes at armature 419 a circuit for stepping magnet 406 of the sender SEN. Magnet 406 therepawl into engagement with another notch in the wiper-driving ratchet wheel, but does not move the wipers 407 and 408. Upon the subsequent deenergization of sending re'- lay 403, it opens the circuit of` stepping magnet 406 of the sender at armature419, whereuponv stepping magnet 406 deenergizes and advances the` wipers 407v and 408 into engagement with the first setof bank contacts. Wiper 407 engages a grounded contact thereby7 closing a circuit for pick-up relay 404. ick-up relay 404, upon energizing, prepares a locking circuit for stop relay 405 at armature 422; closes a circuit for stepping magnet 311 of the sending control sequence switch S at armature 420; and at armature 421 removes the shunt from around armature 418 and its contact so as to permit an interruption to be produced in the outgoing control circuit upon each of the subsequent energizations of the sending relay 403. y At the end of the third interruption produced in the outgoing control circuit, sending relay 403 deenergizes and o ens the circuit of stepping magnet 406 o the` sender, whereupon thewipers 407 and 408'are advanced into engagement withthe fourth set of bank contacts. Wiper 408 thereupon completes the following circuit: from groundv by way of the stop-conductor-control wiper 513 of the sending-control sequence switch S', the first code-digit stop conductor 341, the first v'wiper 511 of the office register OR, the bank contact upon which it is standing, vthe associated jumper, the third impulse-stop conductor 433, the fourth contact in the bank of wiper 408 of the sender, and stop relay 405 to battery. Stop relay 405, u onenergizing, completes a locking circuit or itself at armature 427, disconnects the deenergized sending relay 403 at armature 426, and at armature 423 vupon energizes and moves the associated ECO che circuit efsfepping magnet 311 et the eiidin'g'ontol vsequence switch S-, whereupbn stepping magnet 311 deenergizes A#i111"lidvirflc'es the 312 and 313 into engagement with the second set of bank When this occurs, the stop-condu'ctor-coirtrol wiper 313 applies ground to the code-'digtstop conductor 343,

. th closing a circuit over the second codeedagitwip'er 5l2,-"the bank Contact -upon whih rt is-stztndi`ng,the associated jumper, 1the 'siii' c'ndutonadthence to battery by Way o' the interruptor contacts and mag- 'net 31:1 of the sending control sequence switch "8. Stepping magnet 811 according- 1y energizes *again yand Vinterrupts its own circuit, whereupon it 'deeiergizes `and 'ad- 'vah'ce'sfihe lwipers 3,1-1 'and 312into engages Iint with the tlrird set'o'f banklcntacts in readiness ito send out the first subscriber dlsaY further result ofthe above pointed AIcui; 'nerza'tin of stop relay 405 of 'the leender, *itclse's at armature 424 a circuit L('.la'ogh'tite Biikcdhtact'u'pon which wiper 407 is stiidi' ',aiid 'Wi' 07 for-stepping 'n'aght 406 Et 'oVK h 2t e 'associated inter- 'contacts cco'rdingl the niagnet 406 the ma'nir o 'abuzzr until the wiper-s 407 una `eos sie stepped@ the Tasts'ftf bnkcoitacts. When Ithis occurs,

- .wipe-r im grounded .and the stepping 'operation ceases. Furmermore, 407,"1n pingfif the bankcontat, gpeh's the circuit `o` pick-up ',lay nPi" -up 2relay 1404, however, lis

'and does vnot -iniine- 'liat'ely 'Tn the @selector D, Fig. 5, each time Tthe outgoing "control circuit 'is interrupted by iii l4'03,as pointed out abovefline -Vifea-'tical magnet asfllws: froing'i'ound b way of resti Contact andy armatureli,

its-resting contatta arma- 'ture 78 andiits wdrki i contact, yseries lrelay e7, .and vetcal magnet I2-'to battery. By the 'successive o' `rationsbf 'vertical magnet 7 2, the wipers 'l ,ginclusiveyof'the'selecvtrA .'a'leraised 4step by stepnntlthey stand positefthe -desiied level of bank contacts. 'EL ay 67, ris energized in sries with vertica] imagmmeupn the first impulse ef current passing through it and, 'being slow acting, 'maintains its armature attracted lthroughout the vertical movement.V Relay `67, upon energizing, ,prepares at armature 79 *a fcircuit 'which v is completed through Iinteupter contacts '74 and of normal contacts 75 for lstepping miluy'responsive to the unsure orion "mami contacts 75 when 'the switch share moves its nemici position. 'iieiiiing relay 68 Ea iekiagefeuitfofase t nantais so, una

atfarmature 81 prepares a circuit for rotary magnet 73.

Upon the cessation of the vertical movement, 'slow acting series relay 67 deenergizes and completes the circuit of rotary magnet 73 at armature 79. Rotary magnet 73 thereupon energizes and advances the switch wipers 86-88, inclusive, into engagement with the' first set of bank contacts in the selectedlevel, and near the end of its stroke, opens the circuit of stepping relay 68 at in- `te`frupter contacts 74. Relay 68 accordingly deenergizes and opens the circuit of rotary magnet 73 at'armature 81, whereupon rotary magnet 73 deenergizes also and again closes lits interruptor contacts. In case the trunk terminating in the first set of bank contacts is idle, switching relay 69 energizes immediately. Assuming the trunk to be busy,

however, switching relay 69 is short circuited by the ground potential encountered on the busy test Contact by test wiper 87 and does not. energize. Under these conditions, -test Vrelay '68 is again energized, this time ythrough testwiper 87, and, in addition `to 'closing its usual locking circuit at armature '80, vit vagain vcompletes Ithe circuit of rotary magnet 73 at armature 8l, whereupon the wipers are advanced another step in the above manner.

This alternate operation of stepping relay 68 androtary -kmagne't 73 continues as desi'ibeduntil an idle trunk is reached, which -trunk it will be assumed is the one terminating in bank "contacts 8991, inclusive, and comprising conductors 92-94, inclusive. l such -idletrunk is reached, switching relay 69, being no 'longer 'short circuited, energizes in series with stepping relay '68 andffrom 'the groundedrelease trunk condutor 63. VStepping relay '68, however, is not operatively energized at this time von accuntof the'high resistance of switching re- `1ay'-69. Switching relay 69, upon energizing, opens the test circuit and prepares the l1y ding 'circuit at armature 83; removes ground'fromarmature y76 of line relay 65 at armature 84, thereby opening the circuit of release relay`66; a'nd at armatures 82 and 85 disconnects conductors 62 and 64 from relay '65 and extends them by wa of wipers 86 and`88,bank contacts 89 an 91, and trunk conductors 92 land 94 to the windings of the l li'n`e1rela`ry o'f the thousands selector E in the desired ofli'ce, '#2'. Accordingly, the line and release relaysof the selector E (not shown) 'energize and the-latter preparesthe switch for oper- 'tioni'n the'usual manner. I

'Returning nowr tothe'director, slow -act- 'fpi'ckiup 'relay 1404 of the sender, Fig. 9, final y deenergizes 'and opens the locking circuit 'oftheslow vacting stop relay 405 'at 'armature 422. Accordingly, slow acting relay deenergizes -after an interval and which, inlthis case, is oiiice again connects up sending relay 403 at armature 406, whereupon the sender is started to send out the first subscriber digit 5. It may be pointed out at this time that the interval required for relays 404 and 405 to fall back one after the'other, as described above, is utilized by the selector D in performing the change-over and trunk-hunting operations above described.

The sender has been restarted, as pointed out above, and is now sending out the first subscriber digit 5, and when the lifth interruption in the outgoing control circuit occurs, the following deenergization of sending relay 403 is followed by the advance of the wipers 407 and 408 into engagement with the sixth set of bank contacts, whereupon y stop relav 405 energizes over the following circuit: from ground by way of the stop conductor control wiper 313 of the sending control sequence switch S', Fig. 8, the third associated bank contact, the first subscriber digit stop conductor 351, wiper 605 of the digit register DR-l, the sixth associated bank contact, the right-hand armature of relay 610 and `its resting contact, the fifth impulse-stop conductor 435, the corresponding contact in the sender bank, wiper 40S, and stop relay 405 to battery. Responsive to theener 'zation of stop relay 405, the first subscri er digit is terminated in the usual manner and the wipers of the sequence switch S' are advanced one vstep responsive to the opening of the circuit of steppingl magnet 311 at armature 423.

In the called exchange, the selector E raises its wipers opposite the fifth level responsive to the operationv of the sender above (escribed and then selects an idle trunk, which trunk,rit will be assumed, is the one comprising conductors 101-103, inclusive, and extending to the wiper selecting hundreds selector F', Accordingly, line relay 122of the selector F is energized-overA the callingr loo and closes at armature 131 the usual circult for release relay 123. Release relay 123 thereupon energizesv and places ground on release trunk conductor 102 at armature 132; opens a point in the circuit of release magnet 162'at armature 133; and at armature 134 shunts the lower winding of relay 101 around oif normal contacts 163 for a purpose to be described hereinafter.

In the director, the wipers of the sendingcontrol sequenceswitch S are now in engement with the fourth set of associated ank contacts and ground is applied to the special wiper selecting stop conductor 355 by the stop-conductor-control Wiper 313.

` This stopping ground is extended through armature 527 and its vresting contact and armature 530 and its working contact (relay 523 having been energized as hereinbefore pointed out), to the third impulse-stop conductor 433. Accordingly, the next digit to be sent out is the digit 3 which is sent out in the usual manner and which is terminated upon the energization of stop relay 405 from the ground potential applied to the third impulse stop conductor 433 over the above traced circuit. At the end of the transmission of this wiper selecting digit 3, the wipers of the sequence switch S are advanced another step in the usual manner and ground is applied tothe hundreds-digit stop conductor 352 by the stop-conductor-control wiper 313. v

In the selector F', Fig. 6, line relay 102 is deenergized three times momentarily, responsive to the sending out of the above mentioned wiper selecting digit and, accordingly, three impulses of current are transmitted at armature 31 to vertical magnet 164 by way of armature 133 and its working conf tact and series relay 124. By the operation of vertical magnet 164, the shaft of the switch is raised three steps and carries the wipers opposite the third level of bank contacts. The switch shaft also engages the shaft springs and closes the contacts 104 and 105 which are both placed so as to be operated when the shaft is raised three steps, as is indicated on the drawings. Upon the closure of wipers and connects up the lower set'of wipers. Slow acting series relay 124 is energized throughout the vertical movement and closes a point Ain the circuit of stepping relay 125. Stepping relay 125,` however, does not energize on account of the fact that its circuit is open at armature 130 of relay 121. Series relay`124 also maintains the ground potential disconnected from the shaft contacts 104 at armature 135.v

At the end of the vertical movement, series relay 124 deenergizes and closes at armature 135 a circuit for release magnet 162 which includes the shaft spring contacts 104, resting contact and armature 128, and off normal contacts 163. It will be noted that the lower Winding of relay 121 is included in this circuit eXcept for the fact that it is shunted by ofi' normal contacts 163. VResponsive `to the closure of this circuit, release magnet 162 energizes and closes at armature 161 a locking circuit for itself independent of armature 135 and the shaft spring contacts 104. Re-

f lease magnet 162 also permits the shaft of the opening the olf normal contacts 163. When this occurs, relay 121 energizes; closes alocki I circuit for itself and opens a point in the initial circuit of relay 127 at armature 129;

closes a pointl in the clrcuit of`stepping relay ,-5 125 at amature 130; and at armature 128 opens the circuit of its lower winding and release magnet 163, whereupon release magnet 163 becomes` deenergized.

The net result of the transmission of the preliminary digit 3, it will be noted, is that the 4selector F has been raised to the third level, whereupon the wiper switching relay 122i `became energized and disconnected the upper set of wipers and connected up the lower set ofV wipers-and the shaft and wipers have been restored to normal preparatory to the reception-of the hundreds digit.

In the director, the hundreds .digit 0 is now transmitted and is terminated responsive to the energization of stop relay 405 over the tollowing circuit: from ground by way of vthe stop ,conductor control wiper 313 of the uence switch S, Fig'. 8, the lfifth associated ank contact, the` hundreds digit stop y .as conductor 352, wiper606 of the second digit register Dlt-f2, the eleventh associated bank contact, the tenth impulse stop conductor 4,40, the associated contact in the sender bank, wiper 408,and stop relay 405 to battery. Reao sponsive to the energization of stop relay 405,

the circuit of stepping ma et 311 of the sequeme switch Sv 1s o ne at armature 423 and the wipers 312 an 313 are advanced into t with the sixth set of bank contacts. Y

In the selector F', Fig. 6, line relay 122 is deenergized ten timesjmomentarily inrespgnse to the above described. operation of t vsender and, upon each deenergization, closes the previously traced circuit of vertical magnet 164. `B the operation of vertical magnet 164, t e vswitch wipers are raised o posite the tenth level of bank contacts. ries relay 124 is again maintained energized throughout the vertical movement and in. conjunction with olf normal contants 16.7, which close upon the first vertical step,lcompletes at armature 136 a circuit through armature 130 and its working contact and interrupter contacts 166 for Starring relay Stepping relay 12.5, upon energizing, closes a locking'I circuit for itself at armature 137, and atarmature 138 reparos a circuit for rotary magnet 165. giron, this point, Ythe operation of the se- F'- isidentical with the operation of the selector D previously described. Briefly, the rotary movement is initiated upon theV deenergization of slow actin Series relay 124 .at -the end of the vertica movement and continues until an idle trunk isv reached b the wipers 4150452, inclusive, which time it will; be assumed is the one co conductors 153-155, inclu- IF sive, an xtending to the connector H?.

When this occurs, switching relay 126, be-

ing no longer short circuited, energizes in series with stepping relay 125 and switches the connection through to the selected set of wipers at armatures 139, 140 and 142, and at armature 141 opens the circuit of release relay 123 which subsequently deenergizes and removes the lower winding of relay 121 from around oil normal contacts 163 so as to prevent the said lower winding from interfering with the regular releasing operation ofthe selector which is to 'take place subsequently.

In the connector H2, line relay 201 now energizes over the calling loop responsive to the above mentioned seizure of the associated trunk and closes at armature 209 a circuit for release relay 203. Release relay 203 thereupon energizes; opens a point in the circuit of release magnet 231 and prepares a circuit for vertical magnet 230 at armature 212; prepares a circuit for the upper Winding of switching relay 208 and for ybusy relay 206 at armature 211; and at armature 210 places ground on release trunk conductor 154.

In the director, when the sender is res started, it continues to operate until ten impulses of current have been sent out, at which `time stop relay 405 is energized over the followingcircuit; from ground by way of stopconductor-control wiper 313 of thesequence switch S', the sixth associated bank contact, the tens digit stop conductor 353, wiper 60T of the third subscriber di 't register DR-V-3 the eleventh associated ban contact, the tenth impulse stop conductor 440, the associated contact of the sender bank, wiper 408, and relay 405 to battery The energization of stop relay 405 terminates thetens digit in the usual manner andV also results in thek advance of the sequence switch S into engagement .with the nextk set of bank contacts, whereupon stop-conductor-control wiper 313 applies ground to the special stop conductor 356, which stop conductor is connected through armature 352 and its Working con-y tact (relay 525 having been energized in se,- ries with relay 523 as above pointed out) ,and

conductor 548 towiper 604 of the first or thousands digit register DR-L Since wiper 604 has been advanced into engagement with the sixth associated bank contact in response to the calling of the thousands digit 5, as above pointed out, theground potential is extended hy wiper 604 to conductor 549 and thence through armature 533 and its working contact to the skip conductor resulting in the usual operation of the sequence switch S to automatically advance its wi ers to the next set of bank contacts. Accor ingly, the extra set of eleven preliminary impulses cannot be delivered to the connector H2 between the tens and units digits, and the upper sety of wipers will therefore be used to complete the connection which is to be extended to the line of substation A which terminates in the upper bank of connector H2.

In the connector H2, line relay 201 deenergizes ten times momentarily responsive to the above operation of the sender and, upon each deenerglzation, completes a circuit for vertical magnet 230, the circuit at the time of its first closure being as follows: from ground by way of armature 209 and its resting contact, armature 212 and its working contact, the contact of off normal spring 229 and said spring, series relay 204, and vertical magnet 230 to battery. By the operation of vertical magnet 230, the shaft and wipers of the connector H2 are raised step by step until the latter stand opposite the tenth level of bank contacts. Relay 204 is energized in series with vertical magnet 230 and, being slow acting, maintains its armature 213 attracted throughout the vertical operation and maintains its own circuit and that of vertical magnet 230 intact after the ol normal springs have shifted as they do upon the first vertical step.

At the end of the vertical movement, slow acting series relay 204 deenergizes and shifts the impulse lead from the vertical to the rotary magnet.

In the director, the sender is again started to operate after the usual interval between digits and transmits the last digit in the number. This digit is terminated upon the energization of stop relay 405 of the Isender through the stop-conductor-control wiper 513, the eighth associated bank contact, the units-digit stop conductor 354, wiper 608, the bank contact upon which it is standing, the associated impulse-stop conductor, and wiper 408 of the sender. Upon the energization of stop relay 405, the last digit in the number is terminated and the wipers of the sequence switch S are again advanced one step in the usual manner. At this time, the wiper 313 grounds the last contact in its bank and accordingly grounds conductor 59,

thereby closing a circuit which extends from i ground by way of the said conductor 59, the associated contact in the bank ofr wiper 55 of the secondary switch SS, Fig. 5, wiper 55, working contact and armature 51, armature 39 and its working contact, and switching relay 37 to battery. Switching relay 37 of the trunk circuit TC thereupon energizes and locks itself to the grounded release trunk conductor 63 at armature" 44, and at armatures 43 and 45, disconnects conductors 25 and 27 from the windings of line relay 35 and extends them to trunk conductors 62 and 64, respectively, thereby bridging the calling line across said conductors 62 and 64 and at the same time disconnecting the control circuit of the sender from across the said conductors. Line relay 35 deenergizes responsive to beingv disconnected at armatures 43 and 45 and opens the circuit of releaseV relay 36 at armature 38. Release relay 36 accord ingly deenergizes after an interval and removes ground from release trunk conductor 63 at armature 40, leaving the established connection to be held up by the ground potential applied to release trunk conductor 154 by release relay 203 of the connector H2, Fig. 7. Release relay 36 of the trunk circuit T C also opens the circuit of switching relay 46 of the secondary switch SS at armature 41, whereupon switching relay 46 deenergizes and disconnects its wipers, thereby freeing the director.

In the director, release relay 402 deenergizes responsive to the removal of ground from the release trunk conductor 58 when the director is freed as pointed out above and closes at armature 416 the normal restoring circuit of the sender SEN which is effective only in case the director is freed while the sender is not in its normal posi tion. As a further result of the deenergization of release relay 402, it closes at armature 415 the normal restoring circuit of the sending control sequence switch S', whereupon the-wipers 312 and 313 are advanced the remaining step to their normal position,

magnet 313 being energized through wiper 312. As a still further result of the deenergization of release relay 402, it applies ground to release conductor 401 at armature 417, thereby closing a circuit for the release magnet of thel sequence switch S, for the release magnet of the oflice register OR, and for the release magnets of digit registers DR-1-DR-4, inclusive. l When this occurs, release magnet 307 of the sequence switch S energizes through the associated oil'l normal contacts 308, and the wipers 309 and 310 are restored to normal position in the usual manner, whereupon the circuit of release magnet 307 is opened at off normal contacts 308. Release magnet 502 'of the office register OR is energized through the associated oifnormal contacts 501, whereupon the wipers 511-514, inclusive, are restored to normal position in the usual manner. The digit registers YDR--1-DR-4, inclusive, are restored to normal position in the same manner as the sequence switch S. y y

Responsive to the` restoration of the wipers of .the oilice register OR to normal, relays 523 and 525, Fig. 10, and-relay 609, Fig. 11, deenergize. y

rlhe various' pieces of apparatus ofthe director have been restored to their normal positions andthe director is now in readiness to handle another call.

In the connector H2, Fig. 7, line relay 201 is momentarily deenergized for each of the interruptions produced in its circuit by the herein'before described operation of the sender in sending out ythe last digit of the number, and upon each deenergization, line relay 201 closes a circuit for rotary magnet 2132 as (follows: from ground by way of armature 209 and its resting contact, armature 212 and its workin contact, normally opened contacts control ed by oil' normal spring 229, armature 213 and its resting contact, resting contact and, armature 219, ar-

;mature 220 and its resting contact, and rov tary magnet 232 to battery. By the operation of rotary magnet 232, the wipers 251-253, inclusive, and the wipers 261263, inclusive, are rotated step by step until the former come into engagement with the bank contacts 254-256, inclusive, of the line of substation A The wipers 261-263, inclusive, it may be pointed out, do not engage any of the associated bank contacts owing to the fact that the extra series of eleven impulses were not transmitted between the tens and units digits.

Bela 207 of the connector is energized in mltip e with rotary magnet 232 and, being slow' acting, maintains its armature attracted throughout the rotary movement. Upon energizing relay 207 disconnects test wiper romth 252 e upper winding of switching relay 208 `and connects it to busy relay 206, and at armature 222 places a shunt around amature 219 and its resting contact as a precautionagainst the circuit of the rotary magnet being opened at armature 219 in case busy relay 206 energizes during the rotary movement due to wiper 252 Vpassing over grounded test contacts.

ssuming the called line to be busy, busy lrelay 1s energized through test wiper 252 and from a ground potential encountered on the busy test contact 255 and prepares a locking Vcircuit for itself at armature 218; opens a point in the circuit of the rotary magnet at armature 219; and at armature 220 connects the busy lead tothe Alower heavy talkin` conductor, thereby sending a busy signa ling current backover the established connection to the called substation. Y When relay 207 deenergizes, it disconnects rotary magnet 232 from' the impulse V circuit at armature 222 (armatureA 219 havvugbeen operated), and at armature 221 comp etes' the locking circuit for busy relay 206 and disconnects test wiperr262 from the said b relay.

e calling subscriber, upon hearing the busy tone, replaces his receiver, whereupon the established connection is released in a manner to be explained hereinafter.

In the resent case, however, it will be assumed that the line of substation A' is idle when called as hereinbefore described, in which case busy relay 206 is not energized when the wipers 251-253, inclusive, come to rest upon the terminals of the called line and, when slow acting .relay 207 deenergizes Yat the end ofthe rotary movement, it

disconnects test wiper 252 from the winding of busy relay 206 and connects it to the upper winding of switching relay 208 at armature 221, thereby closing a circuit for switching relay 208 as follows: from ground by way of the working'contact and armature 211, ar-

mature 218 and its resting contact, upperV winding of switching relay 208, resting contact and armature 221, test wiper 252, test contact 255, and thence to battery by way of the switching relay and stepplng magnet of the associated line switch (not shown),

which line switch may be the same as the line switch C, associated with the lineof substation A. Responsive to the closure of this circuit, the switching relay of the called line switch energizes part'way in the usual manner and disconnects the bridge across the line conductors thereat. y y

In the connector H, switching relay 208 energizes. over the above traced circuit and at its lightly adjusted armature 221 closes a locking circuit for its lower winding; disconnects rotary magnet 282 and slow acting relay 207 at armature 220; places direct ground on the test wiper at varmature 224;

and at armature 223 and'227 connects `up the line wipers, whereupon ringing current pro'ected out over the called line to rin the ri ged bell at the called substation. y his ringing current returns by way of the upper line wiper 251 rto' battery by way of the upper winding of rin cut-oil relay 205.

When the call the ringing of his bell byV removing his receiver, a direct current bridge is closed across the associated line conductors, whereuponring cut-o relay 205 energizes; closes a locking circuit for itself atv its lightly adjusted armature 216 and at armatures 214 and 217 disconnects the line wipers from its own upper windingand the generator lead and connects theminstead to the windings of the back brid e battery feed impedance 202. The desire connection is now completed and thejsubscribers may converse as ilo desired. y

When the conversation is completed, the

two, subscribers replace their receivers.

When the receiver is replaced at the called substation A,vtalkingbattery merely ceases to flow in the called line, but when lthe receiver is re laced at substation A, the circuit of line re ay 201 of the connector H2V is opened, whereupon line relay 201 deenervas subscriber `responds to ico ' ics gizesand opens the circuit of release relaym 203. Release relay 203, upon energizing after an interval, removes ground from release trunk conductor 154 at armaturev 210, and at armature 212 completes a circuit vfor release magnet 231 through 'off normal contacts 228, whereupon the switch is restored to normal position in the usual manner. i

Responsive to the removal of the ground potential from conductor 154, ring-cutfotl' 'inw relay 205 and switchingrelay 208 of theconnector H,r'elays 121, 126, and 127 of' the 'fi selector F', the switchinfr relay (not shown) of the selector E', switching relay 69 of the selector D, switching relay 37 of the trunk circuit TC, and switching relay 14 of the line switch C all deenergize. Responsive to the deenergization of the relays mentioned, the associated switches are released in the usual manner. The entire connection is now released and the apparatus involved therein may noyvl be used in setting up a subsequent connection.

In order to explain how the necessary translation is eilected when the thousands digit is above 5, and in order to explain how the lower set of wipers of the connector H2,

Fig. 7, are used when such translation of the f oflice digit takes place, it will now be assumed that the subscriber at substation A desires t-o converse with the subscriber at substation A2, Fig. 7. It will be assumed further that, when the receiver is removed at substation A, the line switch C selects the trunk circuit TC, and that the secondary switch SS selects the director shown in the l drawings. Accordingly, responsive to the manipulation of the calling device in accordance with the oice digits belonging to office #2', the wipers of the olice register OR, Fig. 10, are raised opposite the desired level f in the hereinbefore described manner, and

are then brought into engagement with the set of bank contacts 564 of the oiiice #2' as before explained.

Responsive to the manipulation of the calling device at substation A in accordance with the four subscriber digits 0000, the digit registers DR1DR-4, inclusive, are set upon the corresponding bank contacts inthe usual manner.

The oce code is at this time sent out in the same manner as hereinbefore described, (operatin the selector Dto seize the selector E), a er which the stop conductor conl trol wiper 313 of the sending control scquence switch S is advanced into engagement' with its third bank contact, thereby placing ground through the thousands digit stop conductor 255 of the wiper 605, which as explained hereinbefore has been advanced J ten' steps and Vis now in engagement with the last of its bank contacts. Since relay'609, Fig. 11, is energized through the lower wiper of the oice register and through conductor 542, the last contact in the bank of wiper 605, is now Vdisconnected from the tenth impulse stop conductor 4 40 and is connected instead'to the fifth impulse stop conductor 435. Accordingly, the thousandsdigit to be K sent out is the thousands digit 5, which *causes the selector E', Fig. 6, to be raised to the fifth level to select a hundreds selector in the corresponding group, the selector F', for example, in the same manner as described hereinbefore.

Since relay 523, Fig. 10, is energized as in the precedin example when the substation A' was cal ed, the wiper-selecting digit 3 is delivered to the selector F', causing it to select the lower set of wipers in the same manner as before. dreds digit 0 is delivered to the selector F in accordance with the setting of the digit registerDR-2, Fig. 11, resulting in the wipers of the selector F' being raised to the tenth level to select an idle connector in the corresponding group, the connector H2, for example. Y,

In accordance with the setting of the digit register DR-3, the tensV digit 0 is delivered to the connector H2, whereupon its wipers are raised opposite the tenth level of bank contacts. Upon the termination of this digit, the wipers 313.01: the sequence switch S are advanced into engagement with the seventh bank contact, in which the special stop conductor 356 terminates. Ground is accordingly extended over stop conductor 356 and through armature 532 and its working contact (relay 525 being energized in series with relay 523), to wiper 604 of the thousands-digit register DR-l, by way of conductor 548. Since wiper 604 is standing on the last half of its bank instead of the first half, the ground potential is not extended to the skip conductor as it was in the case just described when the called subscriber was the one at substation A', but is extended instead through conductor 550 and armature `534 vand its working contact, to the eleventh into engagement with the desired set of contacts responsive to the transmission of the units digit. In the director, wiper 313 of the sending control sequence switch S' is advanced into engagement with theV eighth associated bank contact in the usual manner, following'the transmission of the above mentioned series of eleven impulses, and the last digit 0 is set out in the hereinbefore described manner, whereupon the sequence switch S' is again advanced and the director is released and the connectionl switched through as described hereinbefore.

In the connector H2, Fig. 7, the wipers 261-263, inclusive, are advanced into engagement with the bank contacts 264-266, inclusive, responsive to the sending-out of the last digit O. From this .point on the operation is as described hereinbefore.

Referring now particularly to Fig.- 10, it

will be noted that when this director is used in completing a call to a line in oice #2, Fig.- 2, the wiper 513 completes a circuit over one of the contacts 563, the associated jumper, and conductor 542 for the transating relay 609, as is -the case when the #2 is called. Wiper 514, however, in stead of completing a circuit over conductor 548 for the relays 523 and 525 in series, as is the case when oce #2 is called, completes a circuit overrconductor 544 for the. relays 524 and 525 in series. Accordingly, the Wiper selecting digit Vto be delivered to a hundreds selector, such as the hundreds se lector F', Figs. 2 and 6, is two instead of three, amature 531 of relay 524 connecting conductor 355 to the second impulse-stop conductor 532 instead of to the third impulse-stop conductor 433, as isthe case when relay 523 is energized. Otherwise the number received by the director and intended for oilice #2 is handled just `the seme as describedV hereinbefore v-for a number received by the director and intended for oice #2,-

When a call is received by the director which is intended for oiiice #1, Fig. 1, the

director mud; not send out a wiper selecting digit just prior to the sending out of the hundreds digit, on account of the fact that the hundreds selector F, Fig. 1, has only one set of wipers. Accordingly, the fourth bank contact in thev set allotted to oce #1, Fig. 10, instead of being connected to either of the conductors 544-and 545, isV

connected to conductor 543, and relay 525 is energized alone and rforms the hereinbefore mentioned function of shifting the circuits so that the sending out of the extra 'series of eleven preliminary impulses by the tens and units digits is dependent upon the thousands digit dlalled. s

When a call is received by the director shown, that is intended for a line in oiiice #3,

brought into engagement with the bank contacts 565, Fig. 10,'as is indicated in the drawtulgns 'In this se, the bank contactV on w 'ch the third wiper 513 of the oice register OR standsis connected by means of a iductorat armature 527. and extends it by way of conductor 548 to wiper 604 of the thousands-digit register DR-L Relay 522 all connectsJ the two conductors 549V and Fig. 3, the'wipel's 511514, inclusive, arek to the conductor 542, as explainedk Vin connectlon with the preceding example,

550 coming from the contacts in the bank of Wiper 604 to the second and third impulse stop conductors 432 and 433, respectively. Accordingly, after the thousands digit is transmitted and before the hundreds digit vis transmitted, either the digit 2 or the digit 3 will be transmitted in order to effect the correct wiper selection at the twenty group hundreds selector F2. This wiper selection is controlled in vaccordance with the thousands digit registered by the thousandsdigit register DRI- 1, and if the thousands digit is from 1 te 5, inclusive, the wiperselecting digit 2 is sent out to select the upper set of wipers of the selector F2, and if the thousands-digit register is from 6 to 0, inclusive, the wiper-selecting digitA 3 is sent out, resulting in the lower set of wipers of the selector F', Fig. 3, being selected.

It will be noted that in this case, it is not necessary to make any arrangements for controlling the `selection of the wipers of the connectors, such as connectors H and H", owing to the fact that these connectors are of the line type., having only a single set of wipers.

When the director shown is used in completing a` call to oiiice #4, Fig. 4 the wipers of he oliice register OR are brought into engagement with the bank contacts 566 whose .third and fourth contacts are jumpered in lexactly the same Way as the corre sponding contacts associated with oiiicel #3.

Accordingly. when the call is. trunked to the selector El in accordance with the jumpering of thecontacts engaged by the wipers 511 and 512, the number is transmitted in the same manner as explained in connection with oice #3 and the upper set of wipers of the connector in use is employed to complete the connection, the upper set of Wipers of the connectors H5 and H" corresponding to the single set of wipers of the connectors H3 and H4. v

When, however, the present directorY is used to complete a connection to office #4', the wipers of the ofliceregister are brought into engagement with the bank/contacts 567,

whereupon relays 521 and 522 are energized l nection with the trunking of calls' to oices #Brand #4 and relay 521 performs the added function of disconnecting conductor 356 from the skip conductor and connecting it to the eleventh impulse-stop conductor 441, thereby preeldetermining that the Wiper-se lecting digit 11 is to be sent out after the transmission of the tens digit and rbefore the transmission of vthe units digit, so as to cause the lower set of wipers of the connector in use to be used in completing the connection instead of the upper set, as is the case when relay 522 is energized alone.

As pointed outV hereinbefere, either of the i 

